The conventional lehr loaders, such as that shown in U.S. Pat. No. 3,424,030 issued Jan. 28, 1969 to J. L. Mennitt, which schematically shows the physical arrangement of a lehr loader and a cross-conveyor positioned in front of an annealing lehr, are being required to move greater numbers of articles or glass containers onto a lehr mat during a given time period.
Production of glass containers has increased in recent years such that a forming machine now will produce more than twice the number of bottles per minute as they previously did, this being due to the increase in the number of individual sections which form a complete forming machine of the wellknown Hartford I.S. type and also in the fact that many of these individual sections are capable of producing three containers at a time during each cycle of operation of the section. The loader which loads the ware onto the lehr by pushing a line of ware from a cross-conveyor across a dead plate onto the moving lehr mat has created problems in plant operation because it must move faster and is reaching the limit of its mechanical ability to move ware without tipping the ware over.
Another consideration is that because the cross-conveyor is moving at a greater speed in order to move the larger volume of the ware from the machines to the lehr, the loader, even if it is of the type which is illustrated in U.S. Pat. No. 4,067,434 issued Jan. 10, 1978 to E. H. Mumford, which follows in the direction of the movement of ware on the cross-conveyor at the time it moves across the line of ware, has been taxed almost beyond its mechanical capabilities.
Some lehrs may be as narrow as eight feet, while others, as wide as ten to twelve feet, are capable of receiving thirty containers in a row across the width of the lehr. As would be expected, when moving thirty containers at one time by pushing them from a moving conveyor at right angles to this movement onto a dead plate and then onto the receiving end of a moving lehr belt or mat, considerable force will be required. Movement of a pusher bar of this size and the further requirement that it move also in the direction of movement of the ware has become a major consideration in the production speeds of a glass plant. This movement has to be smooth; otherwise, if there is vibration, there is a tendency for the ware to be tipped. Also in these present lehr loaders there is a tendency, if the loader does not move through the row of ware fast enough, that the first incoming container that will form the next row may be struck by the end of the pusher bar, again tipping over a container. In any of the instances when a container is tipped over, it is likely to be damaged to the extent that it cannot be used and, therefore, becomes a discarded piece of ware that must be remelted.
With the foregoing in view, it is an object of this invention to provide a lehr loader in which the pusher bar may be moved forward at a slower rate to avoid high speed impact with the newly formed ware and to push the ware onto the lehr mat with a more controlled velocity than previously capable of being performed by existing lehr loaders. The timing cycle of the movement of the lehr bar is such that it may move back to its position preparatory to moving a row of ware more rapidly than the previous lehr loaders, thus providing additional time in the cycle for moving the ware from the cross-conveyor without interference and with a smoother, unhurried, movement.